The invention relates to the field polymer characterization.
Probing, characterizing, and manipulating single polymers like DNA is often accomplished with the aid of optical methods, e.g., observing evanescent field fluorescence of dye molecules, deflecting light beams in atomic force microscopes, or trapping attached dielectric objects with optical tweezers. There has also been remarkable progress at the molecular level in the study of the electrical ionic conduction signals from voltage biased nanoscale biopores. More recently, a voltage bias on an alpha hemolysin biopore has been shown to induce charged single-stranded DNA and RNA molecules to translocate through the pore. Each translocating molecule blocks the open pore ionic current providing an electrical signal that depends on several characteristics of the molecule. This system has limits for studies of biological molecules: the pore is of a fixed size, and its stability and noise characteristics are restricted by chemical, mechanical, electrical, and thermal constraints.
Thus, there is a need for new apparatus and methods for studying polymer molecules.